At 05:19 PM 8/9/2007, Björn Türoque wrote:

>I have a student dataset that has one record for >each individual course enrollment. I would like >to compute whether or not someone has enrolled >in a course prior to the one they are currently >taking. If a student has taken a course at a >previous date I would like to have a new >variable set up that indicates if this is not their first enrollment. > >I run into a problem with students who enroll in >multiple courses simultaniously. I would like >the data to reflect both of the first courses >with the same start date are the first course >the student enrolls in, instead of as a previous course. > >I have included data below, the variables Ihave >reflects what I have been able to compute, and >the variable Iwant is what I would ideally like to get.

|-----------------------------|---------------------------| |Output Created |13-AUG-2007 11:22:26 | |-----------------------------|---------------------------| StuID CourseDate CourseNum Ihave Iwant

111 09/01/2006 357 0 0 111 09/01/2006 426 1 0 111 01/01/2007 427 1 1 111 01/01/2007 595 1 1 112 01/01/2007 101 0 0 112 03/04/2007 204 1 1 113 03/04/2007 101 0 0 113 03/04/2007 101 1 0 115 09/01/2006 101 0 0 115 03/04/2007 357 1 1

Number of cases read: 10 Number of cases listed: 10

* Try this. SPSS 15 draft output (WRR:not saved separately).

NUMERIC NotFirst (F2). AGGREGATE OUTFILE=* MODE=ADDVARIABLES /BREAK = StuID /FrstDate = MIN(CourseDate). COMPUTE NotFirst = (CourseDate GT FrstDate). LIST.

List |-----------------------------|---------------------------| |Output Created |13-AUG-2007 11:27:26 | |-----------------------------|---------------------------| StuID CourseDate CourseNum Ihave Iwant NotFirst FrstDate

111 09/01/2006 357 0 0 0 09/01/2006 111 09/01/2006 426 1 0 0 09/01/2006 111 01/01/2007 427 1 1 1 09/01/2006 111 01/01/2007 595 1 1 1 09/01/2006 112 01/01/2007 101 0 0 0 01/01/2007 112 03/04/2007 204 1 1 1 01/01/2007 113 03/04/2007 101 0 0 0 03/04/2007 113 03/04/2007 101 1 0 0 03/04/2007 115 09/01/2006 101 0 0 0 09/01/2006 115 03/04/2007 357 1 1 1 09/01/2006

Number of cases read: 10 Number of cases listed: 10 =========================================== APPENDIX: Test data (from original posting) =========================================== Data List LIST / StuID * CourseDate(ADATE) CourseNum Ihave Iwant. Begin Data 111 09/01/06 357 0 0 111 09/01/06 426 1 0 111 01/01/07 427 1 1 111 01/01/07 595 1 1 112 01/01/07 101 0 0 112 03/04/07 204 1 1 113 03/04/07 101 0 0 113 03/04/07 101 1 0 115 09/01/06 101 0 0 115 03/04/07 357 1 1 END DATA. FORMATS StuID CourseNum (F4) /Ihave Iwant (F2). LIST.